Method of producing a mat consisting of filament loop aggregations

Abstract

A method of producing a mat consisting of filament loop aggregations. The first step is that of forming a first filament loop aggregation low in the filament density wherein many filaments are made. These by extruding a thermoplastic synthetic resin out of a T-die and arranging the resin longitudinally and laterally at intervals for continuous molding. The resin is deposited on a boiling water surface. The filament temperature is maintained close to the temperature at the time of molding by heating while the filament bundle is vertically lowered toward a cooling water surface and is sunk into water in the vertical direction. It is lowered at a speed less than the filament extruding molding speed, while a high density thermoplastic synthetic resin layer is conveyed under heating by a conveyer controlled to be at a feeding speed equal to the sinking speed in water of the above mentioned filament loop aggregation and is sunk into the cooling water along the outside of the filament loop aggregation at the delivery end. The filament loop aggregation and thermoplastic synthetic resin layer are fused together on their contact surface.

What is claimed is: 
     
       1. A method of producing a resilient mat having a plurality of bonded filament loops, said method comprising the steps of: extruding a plurality of resin filaments such that they fall toward a cooling liquid;   heating said filaments as they fall toward said cooling liquid to keep said filaments at least close to their extrusion temperature;   maintaining the surface of said cooling liquid in a boiling state such that upon contact of said filaments with said surface, said filaments are caused to wave and bond more than would occur absent said boiling surface;   facilitating the sinking of said filaments below said boiling surface, the sinking of said filaments occurring at a slower rate than the dropping of said filaments into said cooling liquid;   conveying by means of a conveyor located near the surface of said cooling liquid a portion of said filaments prior to their sinking, said conveyor acting to cause the waving and bonding of said portion of said filaments to be different than the waving and the bonding which occurs with respect to those filaments not conveyed, said conveyed filaments ultimately bonding with those filaments that are not conveyed; and wherein in said facilitating step, a directing roller is placed below and near said surface of said cooling liquid and opposite said conveyor, said directing roller serving to direct said filaments below said surface of said cooling liquid as well as limit the width of said filaments as they bond together to the width defined between said conveyor and said directing roller.   
     
     
       2. The method of claim 1 wherein said facilitating step includes adding about 0.05 to 0.02% surface active agent dialkylsufosucinate to said cooling liquid. 
     
     
       3. The method of claim 1 wherein said resin filaments are extruded out of a T-die. 
     
     
       4. The method of claim 1 wherein said roller acts to limit the density of said filaments. 
     
     
       5. The method of claim 1 where there are two pulling rollers below said surface, said pulling rollers acting to connect with and pull said filaments downwardly at a predetermined speed. 
     
     
       6. The method of claim 5 wherein said pulling rollers are located below said directing roller and said conveyor. 
     
     
       7. The method of claim 2 wherein said cooling liquid is held at a temperature of 60 to 80 degrees centigrade such that the surface of said liquid is kept boiling by contact with the heated filaments. 
     
     
       8. The method of claim 2 wherein said heating step involves maintaining said filaments at a temperature of between 150 to 200 degrees centigrade. 
     
     
       9. The method of claim 7 wherein said filaments are dropped through a distance of between 5 to 100 centimeters before reaching said liquid surface. 
     
     
       10. The method of claim 8 wherein said filaments are dropped through a distance of between 5 to 100 centimeters before reaching said liquid surface. 
     
     
       11. The method of claim 1 wherein the conveyed filaments are denser than those filaments which are not conveyed. 
     
     
       12. A method of producing a resilient mat having a plurality of bonded filament loops, said method comprising the steps of: extruding a plurality of resin filaments such that they fall toward a cooling liquid;   heating said filaments as they fall toward said cooling liquid to keep said filaments at least close to their extrusion temperature;   maintaining the surface of said cooling liquid in a boiling state such that upon contact of said filaments within and on said cooling liquid, said filaments are caused to wave and bond more than would occur absent said boiling surface;   facilitating the sinking of said filaments below said boiling surface.